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Topic: Q=mcT question  (Read 2413 times)

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Offline Farbod

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Q=mcT question
« on: February 27, 2013, 06:49:02 PM »
Hello there, I am new to this forum.
I did this exam 2 days ago and there was this question involving using Q=mc delta t.

Now usually, those questions involved heating water by using ethanol and so on. so temp of water increased and Q = Mc delta T was a positive value.

However, in my exam, there was a question about adding magnesium to copper sulphate and that increased the temperature of the final solution, so I knew the reaction is an exothermic reaction.
we I did Q= mc delta T, I put a negative value for Q in this case as reaction is exothermic.

Now I asked a teacher and he said I am right. Now, I just want your opinion to see if I was right.
Of course it makes sense as in this cause, you're loosing heat (exothermic) and also, is asked finally to give a value of enthalpy change per mole of copper sulphate and that was a negative value as reaction is exothermic.

My main concern is the Q value not the final Mol/Kj.

Offline Borek

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Re: Q=mcT question
« Reply #1 on: February 28, 2013, 04:41:53 AM »
Slightly chaotic.

ΔT of what?
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